O Flute Upcut Spiral Router Bits 1/8 in Shank 1.5mm Cutting Dia

Our review of the O Flute Upcut Spiral Router Bits focuses on small-shop CNC users and hobbyists who cut soft metals and plastics as well as wood. The bottom line: these 1/8 in shank, 1.5mm cutting diameter single-flute carbide bits deliver very clean edges and fast chip evacuation on thin aluminum, acrylic and MDF, making them a strong choice when smooth cuts and good chip removal matter most. They are especially useful for detailed CNC work where a narrow profile and reliable surface finish are the priority.

Key Features

• Material compatibility: Performs well on aluminum, plexiglass, plastic, acrylic and a variety of woods so the same bit can be used across different projects.
• Cutting geometry: The single upcut flute and 25~28 degree helix angle produce clean, non-sticky cutting and a smooth machined surface on finished edges.
• Chip removal: The larger spiral chip space speeds evacuation of chips, reducing heat build-up during continuous CNC passes.
• Size and reach: A 10mm cutting length with 40mm overall length gives decent reach for shallow pocketing and edge profiling on small workpieces.
• Manufacturing quality: Carbide construction with mirror polishing and tight tolerances (error within 0.02mm) supports consistent cuts and repeatability.

Who It's For

This bit is aimed at hobby machinists, small CNC shops and makers who need a narrow, precise cutter for routing thin aluminum, acrylic, plastics and common woods. It is a sensible choice for projects like sign making, PCB milling, small brackets and detailed engraving where a small diameter and clean finish are required.

Users needing very high feed rates on thick stock, heavy-duty production tooling or long-reach cutters should look elsewhere; the 10mm cutting length and single-flute design are optimized for light- to medium-duty work and fine detail rather than bulk material removal at industrial throughput.

Pros & Cons

Pros

• Produces clean, smooth cuts on aluminum and acrylic thanks to the polished single-flute geometry.
• Fast chip removal reduces heat and helps maintain finish on continuous CNC passes.
• Tight manufacturing tolerances give consistent performance between pieces.

Cons

• Feed rate can be lower than some expect, so slower passes are often necessary for best results.
• Some customers reported breakage under harder use, indicating it is not optimized for aggressive machining or misuse.

Specifications

Shank diameter	1/8 in
Cutting diameter	1.5 mm
Cutting length	10 mm
Overall length	40 mm
Flute type	Single upcut spiral
Helix angle	25~28 degrees
Material	Carbide, mirror polished

Our Verdict

For hobbyists and small CNC operators who need a precise, narrow cutter for aluminum, acrylic and wood, these O flute upcut bits offer excellent cut quality and effective chip evacuation at a reasonable cost. They are a good value when used for light to medium detail work, but users should run conservative feeds and avoid aggressive heavy cuts to prevent breakage.

Frequently Asked Questions

Can these bits cut aluminum?
Yes, they are suitable for aluminum and have been reported to cut thin anodized aluminum cleanly when used with appropriate feeds and coolant or air blast.

Will they fit handheld routers?
They have a 1/8 in shank and are compatible with many handheld routers and brands as well as CNC milling and engraving machines.

How long is the cutting edge?
The cutting length is 10 mm, with a 40 mm overall length, suitable for shallow pocketing and profiling.